Originating-Gateway Example

Chapter 7 Configuring and Debugging Fax Services

Debugging the Cisco ATA 186/188 Fax Services

An example debug log for a terminating gateway scenario is show below:

[0]Tx MPT PT=100 NSE pkt c0000000

[0]codec: 4 => 0

[0]Rx MPT PT=100 NSE pkt c0000000

Note The NSE response to the CED tone event is not mandatory; some gateways may not send back an NSE response.

When the Cisco ATA is used as an originating gateway for a fax session, make sure that the following conditions are true:

•The Cisco ATA receives and responds to CED-tone-event NSE packets.

•The NSE payload type is the same for the received and transmitted NSE packets.

•The encoder switchover to G.711 occurs during NSE-packet transaction.

An example debug log for an originating gateway scenario is shown below:

[0]Rx MPT		PT=100 NSE pkt c0000000
[0]Tx MPT		PT=100 NSE pkt c0000000
[0]codec:		4 => 0
[0]Rx	MPT	PT=100 NSE pkt c0000000
[0]Rx	MPT	PT=100 NSE pkt c0000000

Note If your gateway is using a legacy IOS software image, it may not send NSE packets but instead may rely on a straightforward codec switchover mechanism. In this case, a codec switchover event occurs rather than an NSE packet transaction.

Possible Reasons for Failure

If your Cisco ATA does not receive CED-tone-event NSE packets and codec switchover does not occur, the failure may be due to the following reasons:

•The terminating gateway is not configured with fax/modem pass-through.

•The fax pass-through mode used by the terminating gateway may not be compatible with the Cisco NSE method.

If the log shows proper NSE packet transaction and G.711 upspeed for your fax session but the session still fails, check that the following conditions are true:

•The Cisco ATA software image version is 2.14 or above.

•The Cisco ATA model number is ATA186-I1, ATA186-I2, ATA188-I1, or ATA188-I2.

•The fax relay option for the remote gateways has been disabled.

Debugging FAX Mode

When the Cisco ATA is configured with fax mode, only G.711 codecs are used. You must confirm that only 0 (for G.711µ-law) or 8 (for G.711A-law) appear in the Enable encoder and DPKT 1st debug lines. The following example of a debug log shows that G.711µ-law is used:

[0]Enable encoder 0

[0]DPKT 1st: 1491513359 1491512639, pt 0

Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (H.323)

	OL-4008-01	7-11

ATA 188 specifications

The Cisco Systems ATA 188 is a versatile Analog Telephone Adapter designed to facilitate the integration of traditional telephone systems with Voice over Internet Protocol (VoIP) networks. This device has been key in bridging the gap between legacy telephony and modern IP-based communication, allowing users to leverage their existing analog phones while enjoying the benefits of digital connectivity.

One of the main features of the ATA 188 is its ability to connect regular analog phones to a VoIP network, enabling users to make and receive calls over the internet. This significantly reduces calling costs, especially for long-distance and international calls. The ATA 188 supports two phone lines, allowing simultaneous voice calls. This dual-line capability makes it a suitable choice for small businesses or home offices that require multiple lines without the need for extensive infrastructure.

The device is equipped with various technologies that enhance its functionality. It supports the Session Initiation Protocol (SIP) and H.323, making it compatible with a wide range of VoIP service providers. Additionally, the ATA 188 features Quality of Service (QoS) settings, which prioritize voice traffic over the internet, ensuring clear voice quality without interruptions or delays. This is essential for maintaining a professional communication experience, especially in business environments.

Another characteristic of the ATA 188 is its user-friendly configuration interface. It allows users to easily set up and manage their devices through a web-based portal. The configuration process is straightforward, with options to adjust settings such as codec selection, call features including call waiting, and call forwarding functionalities.

Security is also a priority for the ATA 188, as it provides robust protocols to protect call data. The device supports Secure Real-time Transport Protocol (SRTP) and Transport Layer Security (TLS) to encrypt voice traffic and manage signaling securely. This ensures that sensitive conversations remain confidential.

Overall, the Cisco Systems ATA 188 is a reliable and efficient solution for users looking to transition from traditional telephony to VoIP. Its dual-line capacity, compatibility with multiple VoIP standards, user-friendly configuration, and built-in security features make it a valuable asset for both personal and professional communication solutions. In an ever-evolving telecommunications landscape, the ATA 188 remains a relevant and practical choice for integrating legacy telephony with modern internet-based services.

Cisco Systems ATA 188 manual Originating-Gateway Example, Possible Reasons for Failure

Models: ATA 188